The Chinese Urban-rural Dual Economic Structure Model and Analysis

Based on the characteristics of urban-rural dual economic structure in China,we build a dynamic endogenous urban-rural dual economic model closely linked to China's reality,and carry out mathematical economics analysis of optimized conditions for urban and rural sectors. The main results show that:(i) The labor growth rate of urban-rural sectors must be greater than the time discount rate,or else there would be a vicious cycle of diminishing returns in the sectors;(ii) The accumulation rate of physical capital and human capital of urban-rural sectors,and the rate of technological progress,need to be greater than the corresponding depreciation rate plus the time discount rate,otherwise there would be a vicious cycle of diminishing returns in the sectors;(iii) The low accumulation rate in the rural sector,and the occurrence of labor outflow,human capital loss and lack of investment,will expand income gap between urban and rural areas,which is a reason for solidification of urban-rural dual economic structure.

Explore economic restructuring Institutional Analysis based on the urban-rural dual economic structure

China＇ s urban and rural economic and social structures are persisted, perfectly shaped, very typical. Since the new century, the Chinese government began to adjust serious distorted urban-rural relations. New rural construction, total abolition of agricultural tax, the construction of modern agriculture and other major strategic decisions have been introduced; free compulsory education in rural areas, the new rural cooperative medical care, rural public infrastructure, cultural services and other specific measures have been rolled out building. But these still can not slow down our growing urban-rural gap, China＇ s economic and social development is still running under the urban and rural pattern, and the trend has increased.

The Impact of the Upgrading of Industrial Structure in the Yangtze River Delta on the Urban-Rural Income Gap

Firstly,this paper conducts theoretical analysis and current situation analysis,and then proposes research hypotheses.Secondly,using spatial Dubin model and partial differential method,it empirically studies the impact of industrial structure advancement and rationalization on the urban-rural income gap.The results show that:(1)Both industrial structure and urban-rural income gap have significant spatial dependence;(2)The increase in the industrial structure rationalization will narrow the urban-rural income gap in local region,while its spillover effect on neighboring areas is not obvious.(3)The impact of the industrial structure advancement on the urban-rural income gap is not linear.It is first expanded and then narrowed.The industrial structure advancement in the Yangtze River Delta will generally narrow the urban-rural income gap at this stage.Finally,this paper put forward relevant suggestions.

Synthesis,Crystal Structure and Antibacterial Activity of a New Ternary Copper(Ⅱ) Complex with 2,6-Pyridinedicarboxylic Acid and 1,10-Phenanthroline

A new ternary copper（Ⅱ） complex, [C43H27Cu2N7O5][C14H6CuN2O8]＇6.5H2O, has been synthesized by the reaction of copper sulfate, 2,6-pyridinedicarboxylic acid and 1,10- phenanthroline （phen）, and characterized by elemental analysis, IR, UV and X-ray single-crystal diffraction. It crystallizes in triclinic, space group P1, with a = 14.379（5）, b = 15.510（5）, c = 15.835（6） A, a = 78.567（6）, β = 63.594（6）, y = 81.287（6）°, V= 3092.1（19） A3, C57H46Cn3N9O19.5, Mr = 1359.54, Z = 2, Dc = 1.446 Mg/m3, λ（MoKa） = 0.71073 A,μ = 1.101 mm^-1, F（000） = 1362, S = 1.071, the final R = 0.0718 and wR = 0.11960 for 10705 observer reflections （I 〉 2σ（I））. The structure unit of the title complex consisfs of a mononuclear part and a di-nuclear part, and the three copper ions show three coordination modes. Each 6-coordinated geometry of the Cu atom is a distorted octahedral coordination geometry. The 3D supramolecular system is formed by the hydrogen bond O-H-O and π-π stacking interaction between neighboring single cells. The antibacterial activity of the title complex is also studied.

Structure Properties of Ternary Hydrides Ni_(3)A1H_(x)

The structure properties of the ternary hydrides Ni_(3)AIH_(x) are studied by use of the interatomic pair potentials obtained from the first principles electronic structure calculation and Chen-Mobius 3-dimensional lattice inversion method.The heat of formation and volume expansion of the hydrogenized systems are investigated.

Elucidating the promotion mechanism of the ternary cooperative heterostructure toward industrial-level urea oxidation catalysis

From the perspective of electronic structure modulation,it is highly desirable to rationally design the active urea oxidation reaction(UOR)catalysts through interface engineering.The binary cooperative heterostructure systems have been shown significant enhancement for catalyzing UOR,but their performance still remains unsatisfactory for industrialization because of the unfavorable intermediate adsorption/desorption and deficient electron transfer channels.In response,taking the ternary cooperative Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4) heterostructure as the proof-of-concept paradigm,a catalytic model is rationally put forward to elucidate the UOR promotion mechanism at the molecular level.The rod-like Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4) nanoarrays with three-phase heterojunction are experimentally fabricated on Ni foam(named as Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4)/NF)via simple two-step processes.The density functional theory calculations disclose that construction of Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4) heterostructure model not only induce charge redistribution at the interfacial region for creating innumerable electron transfer channels,but also endow it with a moderate d-band center that could help to build a balance between adsorption and desorption of diverse UOR intermediates.Benefiting from the unique rod-like nanoarrays with large specific surface area and the optimized electronic structure,the well-designed Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4)/NF could act as a robust catalyst for driving UOR at industrial-level current densities under tough environments,offering great potential for commercial applications.

Structures and Magnetic Properties of Europium-Transition Metal-Gallium Ternary Intermetallic Compounds with 1:3 Type

The crystal structures and magnetic properties of novel Eu TrGa3-r （T=Pd, It, Rh） in termetallic compounds are investigated by using powder x-ray diffraction and magnetic measurements. EuTrGa3-r crystallizes in orthorhombic structure with space group of Cmcm and Z = 4. There are four kinds of nonequivalent 4c crystal positions in EuTrGaa-r unit cell, which are occupied by 4Eu, 4GaⅠ, 4（GaⅡ, T） and 4GaⅢ, respectively. EuTrGa3-r ex- hibits the complex magnetic states in low-temperature regime, with the three-, two- and one-antiferromagnetic transitions occurring for T=Ir, T=Rh and T=Pd, respectively. It might be due to the Kondo effect： a localized antiferromagnetic interaction of the isolated impurity spins with the surrounding conduction electrons at low-temperature regime.

SYNTHESIS AND STRUCTURE OF SbNB_3(Se_2)_6, A NEW ONE-DIMENSIONAL TERNARY NIOBIUM SELLURIDE COMPOUND

SbNb_3(Se_2)_6, Mr=1347.99, tetragonal, P4/mnc,a=b=9.466(2),c=19.075(3) ,V=1709.0(4) ~3, z=4, Dm=5.2(2)g/cm^3, Dc=5.24g/c^3,λ(Moka)=0.71069 ,μ=287.39cm^(-1), F(000)=2328,T=276(1)k,R=5.9％,Rw=6.9％, for 479 unique observed reflections (1>3σ(1)).The structure is composed of [Nb3(Se2)s]∞ chains along the c axis with Sb atoms inserted between them.

Synthesis and Crystal Structure of a New Layered Ternary Tantalum Telluride TaNi_2Te_3

The title compound was synthesized by high temperature reaction of elements. TaNi_2Te_3, M_r= 681. 15, crystallizes in space group P2_1/m with dimensions a =7. 473(2), b=3. 708(1), c=10. 074(2) A, β=106. 78(2)°, V=267. 3(1) A￣3,Z= 2, D_c= 8. 46 g ·cm￣(-3), P=431. 43 cm￣(-1), F(000) = 570, T= 296K. The structure has been refined to final R = 0. 053 for 963 observations. This layered structure contains square-pyramidal Ta atoms and tetrahedral Ni atoms each coordinated by Te atoms. The layered structure may be considered as chain units ∞￣1[Ta_2Ni_2Te_6], which are linked by zigzag chains ∞￣1[Ni]. The title compound possesses a two-dimensional metal cluster. The structural relationship between this compound and its related compounds is discussed, and this is helpful for designing and synthesizing new layered compounds.

A universal thermodynamic model of calculating mass action concentrations for structural units or ion couples in aqueous solutions and its applications in binary and ternary aqueous solutions

A universal thermodynamic model of calculating mass action concentrations for structural units or ion couples in ternary and binary strong electrolyte aqueous solution was developed based on the ion and molecule coexistence theory and verified in four kinds of binary aqueous solutions and two kinds of ternary aqueous solutions. The calculated mass action concentrations of structural units or ion couples in four binary aqueous solutions and two ternary solutions at 298.15 K have good agreement with the reported activity data from literatures after shifting the standard state and concentration unit. Therefore, the calculated mass action concentrations of structural units or ion couples from the developed universal thermodynamic model for ternary and binary aqueous solutions can be applied to predict reaction ability of components in ternary and binary strong electrolyte aqueous solutions. It is also proved that the assumptions applied in the developed thermodynamic model are correct and reasonable, i.e., strong electrolyte aqueous solution is composed of cations and anions as simple ions, H2O as simple molecule and other hydrous salt compounds as complex molecules. The calculated mass action concentrations of structural units or ion couples in ternary and binary strong electrolyte aqueous solutions strictly follow the mass action law.

Development Path of Urban-rural Integration

The urban and rural areas are regarded as two major components of the regional economic system. Only through joint balanced development of the two can we achieve overall economic optimization and social welfare maximization. But the great social division of labor has separated urban areas from rural areas,which casts the shadow of city-oriented theory on cooperative relations between urban and rural areas. Mutual separation between urban and rural settlements and independent development trigger off a range of social problems. We must undertake guidance through rational development path of urban-rural integration,to eliminate the phenomenon of urban-rural dual structure,and promote the sustainable development of population,resources and environment in urban and rural areas as soon as possible.

A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO_4-H_2O and NaF-H_2O binary solutions and NaClO_4-NaF-H_2O ternary solution

A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions and NaClO4-NaF-H2O ternary strong electrolyte aqueous solutions was developed based on the ion and molecule coexistence theory （IMCT）. A transformation coefficient was needed to compare the calculated mass action concentration and the reported activity, because they were usually obtained at different standard states and concentration units. The results show that transformation coefficients between the calculated mass action concentrations and the reported activities of the same components change in a very narrow range. The transformed mass action concentrations of structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions agree well with the reported activities. The transformed mass action concentrations of structural units or ion couples in NaClO4-NaF-H2O ternary solution are also in good agreement with the reported activities in a total ionic strength range from 0.1 to 0.9 mol/kg H2O by the 0.1 mol/kg step with different ionic strength fractions of 0, 0.2, 0.4, 0.5, 0.6, 0.8, and 1, respectively. The results indicate that the developed thermodynamic model can reveal the structural characteristics of binary and ternary strong electrolyte aqueous solutions, and the calculated mass action concentrations of structural units or ion couples also strictly follow the mass action law.

Spatial pattern of urban-rural integration in China and the impact of geography

Urban-rural integration (URI) is a global challenge that is highly related to inequalities, poverty, economic growth, and other Sustainable Development Goals (SDGs). Existing research has evaluated the extent of URI and explored its influencing factors, but urban-rural linkages are seldom incorporated in evaluation systems, and geographical factors are rarely recognized as the influencing factors. We construct a URI framework including regional economy, rural development, urban-rural linkage, and urban-rural gap. Based on a dataset consisting of 1,669 counties in China in 2020, we reveal the spatial pattern of URI and find a high correlation between the spatial pattern of URI and the relief degree of land surface (RDLS). Using structural equation modeling, we discover that topography has direct ( − 0.18, p < 0.001) and indirect ( − 0.17, p < 0.001) effects on URI. The indirect negative effects are mediated through the infrastructure, and the combination of localized advantages and modern technical conditions could mitigate the negative impact of topography. Finally, we identify 742 counties as lagging regions in URI, which can be clustered into eight types. Our findings could facilitate policy designing for those countries striving for integrated and sustainable development of urban and rural areas.

ACTIVITIES OF CaO AND La_2O_3 IN LIQUID CaO-SiO_2-La_2O_3 SLAGS AND SLAG STRUCTURE

The activity of CaO and LaOin the liquid ternary slay CaO-SiO-LaOhas been de-termined by equilibrating Sn with the slag phase in a graphite crucible under l arm of CO at1600C.The experimental results ,showed that the activity of CaO and LaOchanges slowlywhile the ratio of mole fraction.x/x,is less than unit.hut varies sharply while the ra-rio increases from 1 to 1.2.In addition,by equilibrating Sn with the binary slagBO-LaOsaturated witlt solid LaOat three different temperatures,the relation betweenIgγ~0 and I/T is determined as follows:Igγ~0=-20400/T+11.37(1500-1600C)A random network model of molten silicate structure was applied to CaO-SiO-La2O.It was found that the experimentally determined activity-composition curve of CaO arequalitatively reproduced by the curves calculated with the model,but the curves of LaOareconsiderahly different from the calculated ones.It implies that the model used is over-simpli-fied and that the difference in interaction energy between the metal cations of different valenceand silicate anions should be considered.

Solid State Synthesis and Crystal Structure of K_3SI

A new ternary alkali metal chalcogenide halide, K3SI, has been synthesized by solid state reaction method and structurally characterized by X-ray crystallography. The crystal belongs to hexagonal, space group P63cm with a = 11.699（I ）, c = 5.8279（9） A°, Mr = 276.26, V = 690.8（1 ）A°^ 3, Z = 6, D, = 3.985 g/cm^3, F（000） = 756, μ = 9.913 mm^-1, S = 1.004, R = 0.0719 and wR = 0.2204. The title compound is the first example containing S anion in the ternary alkali metal chalcogenide halides family M3QX （M = alkali metal, Q = chalcogenide, X - halide）, which crystallizes in the hexagonal anti-perovskite structure type.

Evolution Rules of Urban-rural Development and Inspiration for China's Agriculture

Based on urban-rural contrast coefficient,this article designs the agriculture relative development index(ARDI) as indicators measuring the intensity of urban-rural dual structure which is comparable among the countries of the world.This article calculates ARDI of 40 countries from 1980 to 2004.The result shows that ARDI in the developed countries and most of the middle-income countries are rising and yet there are declines in most of the low-income countries.The result also showed that most countries' ARDI will see a decline at the earlier stage of industrialization,so their dual economic structure will also aggravate and urban-rural gap will widen.With the economic development,the tendency will change and ARDI presents a U-shape change overall.The turning point is when a country becomes a middle-income one.

From Shanghai empty-nesters problem of looking of urban and rural dual structure

With the continuous development of political, economic,social, empty nesters and more problems, it is not a simple personal issues, has become urgent to break the social proposition.This paper intr~,duces the concepts at the same time,Further analysis of the current situation empty-nesters of the problem and sort out the history of urban-rural dual structure,Finally, find information put forward some countermeasures and suggestions.

First-Principles Study of the New Layered Ternary Metal Telluride,Eu_(2)InTe_(5)

In this study,we performed first-principles calculations using the VASP(Vienna Ab initio Simulation)software package to investigate the crystal structure,electronic structure,and optical properties of a new layered ternary metal chalcogenide,Eu_(2)InTe_(5).Our results show that Eu_(2)InTe_(5) is a non-zero-gap metal with a layered structure characterized by strong intra-layer atomic bonding and weak inter-layer interaction,which suggests its potential application as a nanomaterial.We also studied the optical properties,including the absorption coefficient,imaginary and real parts of the complex dielectric constant,and found that Eu_(2)InTe_(5) exhibits strong photoresponse characteristics at the junction of ultraviolet and visible light as well as blue-green light,with peaks at wavelengths of 389 nm and 477 nm.This suggests that it could be used in the development of UV(ultraviolet)detectors and other optoelectronic devices.Furthermore,due to its strong absorption,low loss,and low reflectivity,Eu_(2)InTe_(5) has the potential to be used as a promising photovoltaic absorption layer in solar cells.

Ternary compounds and solid-state phase equilibria in Mg-rich side of Mg-Zn-Ca system at 300 ℃

The phase equilibria and compositions in Mg-rich side at 300 ℃ were investigated in Mg-Zn-Ca ternary system through the equilibrated alloy method by using scanning electron microscopy,electron probe microanalysis,X-ray diffraction and transmission electron microscopy.The results show that two ternary compounds T1 and T2 can be in equilibrium with the Mg-based solid solution in Mg-Zn-Ca system.T1 phase is a linear compound with the composition region（molar fraction） of 15% Ca,20.5%-48.9% Zn and balanced Mg at 300 ℃.Its hexagonal structure parameters decrease with increasing Zn content,i.e.a=0.992-0.945 nm,c=1.034-1.003 nm.T2 phase has hexagonal structure with the composition region of 26.4%-28.4% Mg,63.2%-65.5% Zn and 7.1%-8.4% Ca.At 300 ℃,the solubility of Zn in the Mg-based solid solution increases for the addition of Ca,the maximum solubility of Zn is 3.7%.Three-phase fields consisting of--Mg＋Mg2Ca＋T1,--Mg＋T1＋T2,--Mg＋T2＋MgZn and MgZn＋T2＋Mg2Zn3 exist in the Mg-Zn-Ca system at 300 ℃.

TEM Investigations on Layered Ternary Ceramics

Layered ternary ceramics represent a new class of solids that combine the merits of both metals and ceramics.These unique properties are strongly related to their layered crystal structures and microstructures. The combination of atomic-resolution Z-contrast scanning transmission electron microscopy （STEM） and transmission electron microscopy （TEM）, selected area electron diffraction （SAED）, convergent beam electron diffraction （CBED） represents a powerful method to link microstructures of materials to macroscopic properties, allowing layered ternary ceramics to be investigated in an unprecedented detail. Vicrostructural information obtained using TEM is useful in understanding the formation mechanism, layered stacking characteristics, and defect structures for layered ternary ceramics down to atomic-scale level; and thus provides insight into understanding the ＂Processing-Structure-Property＂ relationship of layered ternary ceramics. Transmission electron microscopic characterizations of layered ternary ceramics in Ti-Si-C, Ti-Al-C, Cr-Al-C, Zr-Al-C, Ta-Al-C and Ti-Al-N systems are reviewed.